Resin sealing has been mainly used in the field of element sealing of electronic component devices such as transistor and IC from the points of productivity, cost, and other, and epoxy resin molding materials have been used widely. It is because epoxy resins are well balanced in electrical properties, moisture resistance, heat resistance, mechanical properties, adhesiveness to insert materials, and others. These sealant epoxy-resin molding materials are flame proofed mainly with a combination of antimony oxide and a brominated resin such as tetrabromobisphenol A diglycidyl ether.
In the recent move for regulation of halogenated resins including decabrom and antimony compounds for environmental protection after concern about the dioxins problem, there exist an increasing need for non-nonhalogenated (non-brominated) and non-antimony sealant epoxy-resin molding materials. In addition, bromine compounds are known to show an adverse effect on the high-temperature storage stability of plastic-sealed IC's. It is desirable to reduce the amount of brominated resin also from the viewpoint.
There are many proposed flame-proofing methods without use of a brominated resin and an antimony oxide, including the methods of using a flame retardant containing no halogen or antimony, for example, red phosphorus (see, e.g., Patent Document 1), a phosphoric ester compound (see e.g., Patent Document 2), a phosphazene compound (see, e.g., Patent Document 3), a metal hydroxide (see e.g., Patent Document 4), a metal hydroxide and a metal oxide in combination (see, e.g., Patent Document 5), a cyclopentadienyl compound such as ferrocene (see, e.g., Patent Document 6), or an organic metal compound such as copper acetylacetonate (see, e.g., Nonpatent Document 1); methods of increasing the content of filler (see, e.g., Patent Document 7); and recently, methods of using a high flame-retardancy resin (see, e.g., Patent Document 8); and the like.
Patent Document 1: Japanese Patent Application Laid-Open No. 9-227765
Patent Document 2: Japanese Patent Application Laid-Open No. 9-235449
Patent Document 3: Japanese Patent Application Laid-Open No. 8-225714
Patent Document 4: Japanese Patent Application Laid-Open No. 9-241483
Patent Document 5: Japanese Patent Application Laid-Open No. 9-100337
Patent Document 6: Japanese Patent Application Laid-Open No. 11-269349
Nonpatent Document 1: Hiroshi Kato, Function Materials Monthly (CMC Publishing Co., Ltd.), 11(6), 34 (1991).
Patent Document 7: Japanese Patent Application Laid-Open No. 7-82343
Patent Document 8: Japanese Patent Application Laid-Open No. 11-140277